1. Field of the Invention
The present invention relates to usage measurement collection and analysis within communications networks.
2. Background of Invention
An increasingly large number of individuals use portable computing devices, such as laptop computers, personal data assistants (PDAs), smart phones and the like, to support mobile communications. The number of computing devices, and the number of networks that these devices connect to, has increased dramatically in recent years. Similarly, an increasing number of wireless Internet access services have been appearing in airports, cafes and book stores.
Typically users gain access to these networks by purchasing a subscription plan from a service provider. One type of subscription plan is a flat rate subscription plan. In a flat rate subscription plan a subscriber pays a fee for a billing cycle and is entitled to a set amount of network usage (i.e., a usage quota) during the billing cycle. For example, a user may pay $30 for a month and be entitled to 500 minutes of network time. The usage quota can be specified as a time per billing cycle amount (e.g., 500 minutes per month) or as a data volume per billing cycle amount (e.g., 1000 kBytes per month). In some flat rate subscription plans the usage quota is unlimited.
Another type of usage plan is an actual usage subscription plan. In an actual usage subscription plan a subscriber pays a set rate based on the actual amount of network usage during a billing cycle. For example, a user may pay $1 per minute of network usage. Actual usage plans can have incentives/penalties based on a subscriber's usage during a billing cycle. For example, in a subscription plan a subscriber may pay $1 per minute for the first 500 minutes and $2 per minute for every minute beyond 500 minutes during the billing cycle. Subscription plans can combine aspects of flat rate plans and usage plans. For example, a subscriber may pay $30 per month for 500 minutes of network usage and $1 per minute for every minute used after 500 minutes.
In the plans described above, as well as other subscriber plans, it is useful to police a subscriber's usage against one or more quotas. Usage collection and usage analysis are required steps in policing a subscriber's network usage against one or more usage quotas. Usage collection involves collecting raw usage metrics from network devices. Usage collection can occur periodically throughout a billing cycle (e.g., collect data every week). Raw data is aggregated to calculate usage totals during the subscriber's billing period. Usage analysis involves evaluating a subscriber usage total against a usage quota specified by a subscription plan to determine if the usage quota was breached. If the quota is breached, the service provider applies policy enforcement according to the subscription plan. For example, the service provider may send a message to the subscriber, redirect traffic, terminate the session, or generate a billing record.
Usage collection generates large volumes of data putting loads on both network devices and metering nodes. Thus, this data is expensive to collect. This data is of low value to the service provider if it does not identify a quota breach. Further, usage analysis is expensive to compute and is an intensive input/output operation that does not result in identifying a quota breach in the vast majority (approximately 98% or greater) of evaluations. Typically, the rate of usage quota breaches is very low, because only a small percentage of subscribers (approximately less than 5%) have usage patterns which breach usage quotas during their billing period. Further, the majority of usage quotas are breached during the last few days of a subscribers billing period while evaluations occur throughout the billing cycle.
RADIUS and Diameter protocols are frequently used to gather usage metrics. For further information regarding RADIUS and Diameter protocols, see, e.g., “RFC 2865: Remote Authentication Dial In User Service (RADIUS),” “RFC 4072: Diameter Extensible Authentication Protocol (EAP) Application,” “RFC 2866: RADIUS Accounting,” and “RFC 3588, Diameter Base Protocol,” all of which are by the Internet Engineering Task Force (“IETF”), the disclosure of all of which are hereby incorporated by reference.
A typical Authentication, Authorization and Accounting (“AAA”) transaction consists of the following exchanges: an Access-Request message including subscriber id and credentials, an Access-Accept message including authorized session parameters, Accounting-Interim messages containing cumulative usage metrics for a pre-determined collection interval, and an Accounting-Stop message containing final usage metrics for the session. The Access-Request message will typically result in a database lookup to validate subscriber credentials and to retrieve service profiles. The Access-Accept message can contain an Interim Interval which instructs the node when to send interim usage updates. The Access-Accept message can also contain a Class attribute which contains an opaque octet string that the node will echo back in every usage update (Interim and Final).
The previous method of calculating an interim interval for gathering customer network usage measurement updates only at Access-Request time is not suitable for long lived sessions because the usage breach probability typically increases over the subscriber's billing period.
What are needed are cost effective systems and methods for usage measurement collection and analysis based on the probability that a user will breach the user's quota for allowed network services. Further, these systems and methods should be able to operate within the RADIUS and Diameter protocols.